In the absence of the end of September and of knowing the definitive data of the tourist season, everything indicates that the summer has been one of the good ones, like those before the pandemic.Neither inflation, nor the war in Ukraine, nor the cuts that are coming in the energy horizon have taken away our desire to travel - only the strikes of the cabin staff of some airlines have stopped us.Challenging the elements, we have set out to see the world, further or closer, depending on the tastes and possibilities of each one.Back to normal life, most will have a positive balance of their trips;others, on the other hand, will regret having brought the memory they never wanted: an infectious disease.The news has jumped to the media that more than a hundred tourists have been infected with dengue fever during their trip to Cuba, and dozens of them have had to be hospitalized on their return to Spain.However, although the island has made headlines, “there have also been dengue outbreaks in Singapore, and in 2021 it affected (and still continues) Brazil, India, Vietnam, the Philippines, Cook Islands, Colombia, Fiji, Kenya, Paraguay, Peru and Reunion Islands," lists Agustín Benito, director of the National Center for Tropical Medicine of the Carlos III Health Institute, who attributes the notoriety of the Cuban outbreak "to the growing increase and recovery of international travel and the frequency of tourism from our country to Cuba. , one of the destinations par excellence in the Caribbean”.In addition to Cuba, dengue presents higher figures than in previous years in Brazil, Central America, Indonesia, Cambodia or ThailandThe microbiologist Manuel Linares, president of the IO Foundation -focused on the study of emerging zoonoses, tropical and travel medicine-, highlights that dengue is present in more than 120 countries and this year, in addition to Cuba, "Brazil, Central America , Indonesia, Cambodia or Thailand are presenting higher figures than in previous years”.Every year there are between 100 and 400 million dengue infections - "most of them mild and asymptomatic", and they are going to increase because "it is found in tropical and subtropical climates throughout the world, mainly in urban and semi-urban areas, with a main and highly efficient vector that is 'Aedes aegypti' and 'Aedes albopictus' -known as the tiger mosquito-, which has less vectorial capacity, but can transmit the virus”, adds Benito, also president of the Spanish Society of Medicine Tropical and International Health (Semtsi).And the worst thing is that “these mosquitoes are also vectors of the chikungunya, yellow fever and Zika viruses, so surveillance of these viral pathologies in travelers should not be neglected”.Anyone who thinks they are safe from dengue by not traveling outside our borders is making a serious mistake, because cases of autochthonous dengue have already been reported in Catalonia.The director of the Center for Tropical Medicine recommends that those who are going to travel to areas with risk of dengue “go to a travel medicine consultation and adopt personal protection measures against mosquito bites throughout the day, both indoors and outdoors. outside: use repellents, wear long-sleeved cotton clothing and cover the ankles, wear comfortable shoes and place screens on the windows.”But the great concern of trips to tropical areas is malaria, old known by specialists, so much so that "there is a phrase that any clinician anywhere in Spain and the rest of the world should keep as a priority: traveler or migrant with fever from of tropical and subtropical areas of the planet, the main suspicion and diagnostic search is malaria or malaria”, emphasizes the president of Semtsi.A representative fact: in Spain between 300 and 400 cases of imported malaria are registered each year, a not insignificant figure given that Europe is an infection-free zone.Therefore, he insists that those who are going to travel to regions where there is malaria, in addition to going to the traveler's medical services, should consult the guides on the disease.Travel to Africa, Southeast Asia and some South American countries carries the risk of contracting onchocerciasis, lymphatic filariasis and loiasis, which "are transmitted by arthropod mosquitoes (the first by blackflies or blackflies)".In Spain, the infection is diagnosed through a microscope or serology."The main suspicion comes from the presence of eosinophilia in blood tests in people who come from places where there is transmission."How to prevent?"Avoiding contact with mosquito bites and using insect repellants."The mosquitoes aren't the only bad guys in the movie;also certain worms (helminths) cause schistosomiasis.And here we do not necessarily have to look for the origin in exotic trips, because "there can be cases of autochthonous transmission with our snails as vectors."Bed bugs seem to have returned from a forgotten past, and more and more people are consulting a doctor for bites."Normally, they are a problem during the trip and rarely on the way back because they do not transmit diseases," says Benito.Even so, "it is advisable to avoid bites, inspecting the hotel bed because they could get into the luggage and bring them back home."They are quite resistant to insecticides.One piece of advice is to open your luggage in the bathtub, because bedbugs cannot climb the walls.Scabies is not necessarily a traveler's disease, but many people say they have contracted it during a trip.The team from the Carlos III National Epidemiology Center has published an article in 'Plos One' that analyzes the evolution of scabies in Spain since 2014.The infection, which was "confined" to central and western Africa, jumped to Europe in May and in a short time spread to all continents.The WHO declared it a public health emergency, although "its main routes of transmission are well known."For this reason, the Semtsi spokesman stresses that contagion must be avoided during trips.For his part, Linares warns that “sexually transmitted infections are in the eye of the hurricane globally and, right now, their increase is exponential.The notification of diseases, such as syphilis, gonorrhea or chlamydia, is becoming more frequent, and travelers are no exception to them.The two experts agree that we must be alert to the emergence of a new pathogen.The president of the IO Foundation advises us to get used to hearing the name of a new microorganism every year.“They promise to be news in the short term: West Nile virus, Oropuche, Zika, chikungunya, hepatitis E, Rift Valley fever, Marburg, Mayaro, Nipah... In addition to others that have already given us some scare like Ebola or Crimean-Congo hemorrhagic fever.A non-stop, let's go!"The director of the National Center for Tropical Medicine thinks that the biggest enemy in this field of health "is any zoonosis that can maintain reservoirs in animals that can be anywhere on the planet (rodents, cats, etc.)", and the Monkey Pox is an example of that danger."We will have to watch that it has not been transmitted to animals," he warns.The extreme heat and drought experienced this summer in Europe, America or Asia have favored the proliferation of some of the infectious diseases, such as dengue or malaria.How?“It has been shown that climatic conditions directly influence the dynamics of global expansion of microorganisms.Global warming improves the survival and reproduction conditions of vectors such as mosquitoes, increasing the capacity to transmit diseases... In addition, it expands their expansion to other areas where they were not previously present”, explains Linares.The lack of food due to the drought causes rodents to approach houses, increasing the risk of hantavirus transmissionOn the other hand, he continues, "drought causes food shortages in some areas of the world, causing rodents to get closer to human homes, increasing the risk of contracting diseases potentially transmitted by them such as hantavirus or leptospirosis" .And already in our environment, "the heat means that we cannot be without air conditioning, and legionella outbreaks are frequent due to the contamination of cooling towers without proper maintenance in hotels or buildings."The health problems that threaten travelers give almost as much to count as travel.For this reason, experts never tire of insisting that health advice should not be lacking when planning a trip to a tropical destination.And back, "the presence of fever, skin lesions or persistent digestive disorders also requires medical attention."Objective: not to bring an infectious 'souvenir' from the holidays.In the absence of the end of September and of knowing the definitive data of the tourist season, everything indicates that the summer has been one of the good ones, like those before the pandemic.Neither inflation, nor the war in Ukraine, nor the cuts that are coming in the energy horizon have taken away our desire to travel - only the strikes of the cabin staff of some airlines have stopped us.Challenging the elements, we have set out to see the world, further or closer, depending on the tastes and possibilities of each one.Back to normal life, most will have a positive balance of their trips;others, on the other hand, will regret having brought the memory they never wanted: an infectious disease.